Patent GB-653001-A (GB)
Title: Improvements in or relating to milling machines
IPC: B23Q5/48
Filed: 1948-02-17
Abstract: 653,001. Milling-machines. KEARNEY & TRECKER CORPORATION. Feb. 17, 1948, No. 4633. Convention date, Feb. 27, 1947. [Class 83 (iii)] A milling-machine having a work-table 18, saddle 17, and knee 15 relatively slidable with respect to each other, the knee being vertically movable on a column 10, comprises mechanism for driving the work-table including a rapid traverse clutch 65 mounted in the knee, a reversing clutch 103 mounted in the saddle and hydraulic control mechanism mounted in the saddle and operatively connected to the reversing clutch, and flexible conduits 102, 104 connecting the hydraulic control mechanism with the clutch 65 for effecting co-ordinated control of the reversal of movement and speed changes of the work-table. Feed and rapid traverse shafts 32, 34, respectively, are driven from an electric motor 20 disposed in the base of the column, the shaft 32 being connected by feed transmission and clutch gears to drive the knee, saddle and work-table selectively at feed-rate, and the shaft 34 being connected by the hydraulically-actuated clutch 65 to drive the knee and other slidable members at rapid traverse rate. The clutch 65 is also operable by a hand lever 70. The clutch gears 61, Fig. 4, for driving the work-table are selectively engageable by a slidable collar 64 which is engaged by a shifter 106. The latter is operatively connected to a trip sleeve 112 provided in the saddle, the upper end of the sleeve being adapted to engage a trip-dog 113 on the worktable to move the clutch collar 64 to disconnecting position. The clutch collar is re-engaged when the trip sleeve is rotated by means of a hydraulically-actuated piston 115 movable in a cylinder 155. The clutch collar 64 may also be shifted by means of a hand lever 67. The trip sleeve has slidably mounted therein a post 128 which is moved upwardly to rapid traverse position by applying fluid-pressure to a plunger 130 carried at the lower end thereof. The post 128 may also be moved to rapid traverse position by means of a hand lever 67. In operation, assuming the work-table moving from right to left at rapid traverse rate, see Fig. 5, a dog 137 on the table engages the post 128, moving it downwardly to feed position as one of the work fixtures approaches the cutter. The workpiece is moved at feed rate during the cutting stroke, whereupon a dog 138 on the table engages and depresses a trip plunger 139 on the post 128 to open a valve 143 causing a valve plunger 147 to be moved to the left and the piston 115 also to be moved to the left, thereby rotating the trip sleeve 112 and shifting the clutch collar 64 into engagement with the opposite clutch gear to effect reversal of the table movement. The movement of the piston 115 causes pressure fluid to move the plunger 130 upwardly to rapid traverse position. This has the effect of disengaging asynchronizing and retarding clutch 94 and of engaging the rapid traverse clutch 65. Similarly, as the work-table approaches the end of its movement from left to right, a dog 192 engages a trip plunger 140 to again effect reversal of the table movement. If movement of the work-table at feed-rate is desired, a selector switch 161 in the  hydraulic circuit is turned through 90 degrees. Specifications 499,137 and 499,189 are referred to.